The overall goal of this proposal is to develop a topical microbicide against a broad way of sexually transmitted pathogens by combining multiple protective factors as naturally occurs at mucosal surfaces. Certain antimicrobial lipids and peptides, many of which are found at mucosal surfaces, have the potential to accomplish this goal. The antimicrobial lipid 1-0-octyl-sn-glycerol (octyl glycerol) is a monoglyceride ether which inactivates human immunodeficiency virus (HIV), herpes simplex virus (HSV), Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis by destabilizing their plasma membranes. Antimicrobial peptides, such as magainins and lentivirus lytic peptides, also permeabilize plasma membranes and are known to be effective against sexually transmitted pathogens. Because monoglyceride ethers and peptides destabilize membrane bilayers by different mechanisms, it is hypothesized that mixtures or conjugates of antimicrobial lipids and peptides will be a more efficient microbicide than each compound used individually. Experiments will be done to determine if antimicrobial peptides can be more effectively targeted to the plasma membrane of pathogens by covalently linking octyl glycerol or fatty acids to the peptides. More efficient membrane targeting should increase antimicrobial activity and decrease the amount of peptide required in the microbicide. Reducing HSV production by interfering with N-glycosylation provides an additional strategy for preventing the spread of sexually transmitted diseases (STDs). Retinoic acid (RA) reduces the production of infectious HSV virions while concomitantly altering the N-glycosylation pattern of viral proteins. Studies will be continued to determine how RA changes the glycosylation pattern of HSV proteins. The mechanism by which RA functions as an antimicrobial agent will be used to develop strategies for reducing the shedding of infectious HSV particles. The successful completion of these studies will result in the production of a topical rnicrobicide combining multiple antimicrobial compounds thereby more closely approximating how mucosal surfaces are protected in vivo and filling a critical need for compounds capable of reducing the spread of STDs. This project contributes to the program by producing new classes of microbicides based on lipids, peptides and N-glycosylation inhibitors which will be evaluated m via against HIV , C trachomatis,and a panel of sexually transmitted bacteria and protozoa.. Microbicides shown to be effective in vitro will be formulated for vaginal delivery and tested for efficacy and toxicity in monkeys.